Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple user equipment devices (UE). Each UE communicates with one or more base stations, such as an evolved Node B (eNB) via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the eNBs to the UEs, and the reverse link (or uplink) refers to the communication link from the UEs to the eNBs. This communication link may be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system. In this regard, the UEs can access wireless network via one or more eNBs.
Additionally, LTE radio access functionality has been extended into unlicensed frequency spectrums, such as the Unlicensed National Information Infrastructure (U-NII) band used by Wireless Local Area Network (WLAN) technologies. This extension of cell LTE operation is designed to increase spectral efficiency and hence capacity of the LTE system, and is often provided by small cells. Examples of radio access technologies (RATs) that provide LTE functionality over WLAN technologies include LTE in an unlicensed spectrum (LTE-U). To use resources for communicating in the unlicensed band, LTE-U network nodes perform a clear channel assessment (CCA)/enhanced CCA (eCCA) to determine whether a corresponding channel is available before transmitting communications. In this regard, it may not be possible to determine the exact timeline for transmitting/receiving communications in the network.
In addition, LTE user equipment (UE) or other devices may be configured to operate in a discontinuous receive (DRX) mode where an evolved Node B (eNB) can configure the UE or other devices with parameters defining periods of time during which the UE can activate communication resources (e.g., on-durations) and deactivate (or sleep) communication resources (e.g., off-durations) to decrease power consumption by the UE. When a UE is in discontinuous receive (DRX) mode and is operating using a contention-based RAT, however, the configured on-durations may occur over time periods where the eNB has not been able to successfully acquire a channel for communicating in the unlicensed band. In this example, the DRX on-duration may be wasted, which lessens the effectiveness of DRX for decreasing power consumption at the UE. In addition, in an example, the eNB may acquire the channel and begin transmitting towards the end of the on-duration, and thus the UE may enter an off duration before receiving all communications from the eNB (e.g., and may sleep communication resources based on the DRX mode parameters).